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<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style type="text/css"></style>
   
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<body>
   <script>
       var a= 'abcdef';
       var a=10;
       var a=10.99;
       var a=true;
       var a=false;

       var a=new Object();
       var a=new Array(1,561,61,961);

       var a=null;
       var a=undefined;
       var a=function(){
        alert(666);
       }

       //a();
       
       console.log(a);
       //console.log(typeof(a));
       console.log(typeof a);

   </script>

   
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